Feed mechanism for extrusion mills



July 9, 1957 E, N. MEAKIN 2,798,444

FEED MECHANISM FOR EXTRUSION MILLS Filed NOV. 29, 1952 4 Sheets-Sheet 1 INVENTOR. EDGAR 1v. MEAKl/V BY HIS -/1 T TOR/VEYS July 9, 195 E. N.'MEAKIN 2,798,444

FEED MECHANISM FOR EXTRUSION MILLS Filed Nov. 29, l952 4 Sheets-Sheet 2 INVENTOR. EDGAR Iv. MEA KIN We 9' 6 M H/S' ATTORNEYS July 9, 1957 E. N. MEAKIN FEED MECHANISM FOR EXTRUSION MILLS Filed Nov. 29, 1952 4 Sheets-Sheet 5 INVENTOR. EDGAR 1v- MAK//V l-l/S ATTORNEYS y 1957 E. N. MEAKIN 2,798,444

FEED MECHANISM FOR EXTRUSION MILLS Filed Nov. 29. 1952 4 Sheets-Sheet 4 INVENTORn 1; DGAR N. MEA/(l/V HIS ATTORNEYS Inited States Patent 2,798,444 Patented July 9, 1957 2,798,444 rnnn MECHANISM FOR EXTRUSION MILLS Edgar N. Meakin, Hillsborough, Calif.

Application November 29, 1952, Serial No. 323,297

9 Claims. (Cl. 107--14) My invention relates to pellet mills of the extrusion type adapted for the formation of pellets from granular or like material, and more particularly to mechanism for the feeding of such material to the extrusion chamber of such mill.

The present invention is an improvement on the pellet mill of Edgar T. Meakin patent for Extrusion Mill, No. 2,240,660 of May 6, 1941.

Among the objects of my invention are:

(1) To provide a novel and improved extrusion mill;

(2) To provide a novel and improved feeding mechanilslm for supplying pelleting material to an extrusion m1 r (3) To provide a novel and improved material feed ing means of higher efficiency for an extrusion mill;

(4) To provide a novel and improved material feeding means for an extrusion mill, wherein a maximum extrusion of material will be realized with a minimum expenditure of power;

(5) To provide a novel and improved material feeding means for a pellet mill, which will assure a greater uniformity in the product of such mill.

Additional objects of my invention will be brought out in the following description of a preferred embodiment of the same, taken in conjunction with the accompanying drawings wherein-- Figire 1 is an elevation-a1 view in section through an extrusion mill embodying the features of the present invention;

Figure 2 is a plan view in section, taken in the plane 22 of Figure 1;

Figure 3 is a view taken in the plane 3-3 of Figure 1;

Figure 4 is a view taken in the plane 4--4 of Figure 1;

Figure 5 is a view n the plane 55 of Figure l, with portions of housings removed.

Referring to the drawings for details of my invention in its preferred form, the same is illustrated as embodied in a pellet mill of the horizontal type, basically illustrated in the patent to Edgar T. Meakin, No. 2,240,660 of May 6, 1941, previously referred to. Such mill involves a main housing 1 including a front wall 3 and a rear wall 5 parallel thereto, said walls incorporating aligned main bearings 7, 9 for supporting a "drive sleeve 11 joumaled therein.

The drive sleeve terminates in a drive plate 13 adjacent the front wall of the housing and to this drive plate there is removably mounted a ring die 15.

The manner of securing the ring die to the drive plate involves the use of an intermediate mounting ring 17 which is of somewhat greater diameter than the drive plate and is bolted thereto. The ring die abuts the intermediate ring, and adjacent thereto the ring die is provided with a peripheral groove 19 to receive one edge of a. split cramping ring 21 which straddles the intermediate ring. By such means, the die is clamped to the intermediate ring.

Accurate centering of the ring die with respect to the rotational axis of its dnverneans is assured by forming the inner edge of the ring die with an integralflange 23 which enters a centering or aligning groove in the adjacent wall of the intermediate ring.

The ring die and the drive plate constitute the extrusion chamber 27 for the mill, the pelleting material being fed into this chamber for extrusion through the die by means of a pair of extrusion rollers 29 whose axes lie in a common horizontal plane. These rollers are journaled between parallel plates 31, 33 which are fixedly mounted at the end of a shaft 35, concentrically passing through the drive sleeve and supported on a front bearing 37 within the front end of such sleeve, and a rear bearing 39 having an outer race 41 in common with the sleeve bearing 9. This outer race and associated inner race 43 of the bearing 39 are locked by an interconnecting shear pin 45 to hold the shaft 35 stationary for all normal operating loads.

Rotation of the ring die with respect to the roller positions is accomplished by a drive connection to the drive sleeve. This may take the form of a gear 47 mounted on and keyed to the sleeve within the main housing, and peripherally meshing with IE1 drive pinion 49 on a drive shaft 51. This drive shaft is journaled in aligned bearings 53, 55 in the front and rear walls, respectively, of the main housing, and connects rearwardly of the housing to a drive motor (not shown).

The pellet material feeding means constituting the present invention involves a cylindrical wall casing 57 affixed at one end to the front edge of the ring die, and at its other end, terminates in a front wall 59 having a feed opening 61 therein which is bounded by an inwardly directed lip 63.

In affixing the casing to the front edge of the ring die, the casing is formed with an outwardly directed flange 65 which lies up against the front edge of the die, and is held thereto by a plurality of arcuate trough links 67 having one edge anchored in a peripheral groove formed in the ring die, while the other edge of each. overhangs the flange on the casing. These trough links are coupled by connecting bar links 69 to form a chain, which is tensioned by an adjustable bolt coupling 71 jioining the free ends of such chain.

A housing 73 enclosing the extrusion. chamber and casing, is affixed to the front wall of the main housing and provided with a pellet discharge opening 75 in the bottom thereof and an opening in the front wall in alignment with the feed opening in the casing.

To the front wall of the extrusion chamber housing, there is mounted a feed hopper 77 having a cylindrical lower end portion 79 in alignment with and extending into the feed opening of the casing. This hopper may receive its supply of pellet material from a mixing chamber 89 mounted on and supported by the mill housing 1.

In the cylindrical portion of the feed hopper, there is disposed a spiral feed assembly 81 involving a plurality of spiral blades 83 which extend into the casing and are supported in spaced relationship on a common axis within the cylindrical portion of the feed hopper, by a plurality of brackets 85 uniformly distributed about the feed opening and aflixed to the inner surface of the front wall of said casing. Each inner end of these spiral blades is caused to span a pair of such brackets to which the respective blades are affixed. The various blades are joinedamount of material. As the movement of each spiral progresses inwardly, the material will be fed continuously into the casing and from there into the extrusion chamber.

Upon release of the pellet material by the spiral blade assembly, the movement of the material into the extrusion chamber is guided by a pair of deflector-spreader elements 89 operating in conjunction with the rotational movement of the ring die. Each of the deflector-spreader elements constitutes an arcuate-shaped blade lying at an angle to the axis of the extrusion chamber and extending from substantially the front wall of the casing 57 to a point within the extrusion chamber lying beyond the path of relative travel of the rollers on the die surface.

That portion of each deflector-spreader element within the casing has its outer edge uniformly close to the inner surface of the cylindrical wall of the casing, while that portion within the extrusion chamber has its outer edge uniformly spaced a short distance from the roller-contacted surface of the ring die.

These elements are preferably supported at the extrem 5 ties of a connecting bar 91 which is affixed to the front roller-supporting plate 31 in a position normal to the horizontal plane of the roller axes in order that the deflector-spreader elements will each occupy a position intermediate the rollers. In the actual fabrication of the deflector-spreader elements, they might be formed from a single sheet of material and integral with the connecting bar, and then giving them their angular position by twisting them in opposite directions with respect to said con necting bar.

The twist position of each of the deflector-spreader elcments'shail be such as to cause it to have a component of direction coinciding with the direction of rotation of the ring die, and when so positioned, each of these elements will intercept the material coming from the spiral blade assembly, and in response to rotational movement of the casing and the ring die, will deflect and guide such mateaccordingly, do not desire to be limited in my protection to the specific details illustrated and described, except as may be necessitated by the appended claims.

I claim:

1. In a pellet mill having an extrusion chamber including a ring die and extrusion means including at least one roller movable relatively with respect to the compression surface of said die, means for supplying pellet material to said extrusion chamber, and means for spreading the material delivered from said supplying means on said compression surface, said means including a deflector-spreader element comprising substantially an arcuate-shaped blade extending into said extrusion chamber across the compression surface of said ring die on an angle to the axis of the extrusion chamber in the general direction of rotation of said ring die, with the outer edge of such blade uniformly spaced from said compression-surface.

2. in a pellet mill having an extrusion chamber including a rotatable ring die and stationary extrusion means movable relatively with respect to the compression surface of said die, means for supplying pellet material to said extrusion chamber, and means for spreading the material delivered from said supplying means on said compression surface, said means including a stationary deflector-spreader element comprising substantially an arcuate-shaped blade extending into said extrusion chamber across the compression surface of said ring die, with the outer edge of such bladeuniformly spaced from said rial into the extrusion chamber, for the most part behind '1 the element. Due to the uniform spacing of the outer edge of the element within the extrusion chamber, a uniform layer of the material will then be carried by the rotating die to the roller situated ahead.

Such action of the deflector-spreaders accompanied by the continuous feeding of fresh material from the spiral blade assembly serves to maintain the material in a constant state of agitation. Any tendency of such material to spill out through the feed opening by reason of such agitation is effectively inhibited by the inwardly directed lip The manner of operation of the deflector-spreader elements serves not only to uniformly distribute the material across the path traversed by the rollers, but each roller will be fed a like amount of material, and, as a result, the extrusions around the die surface will be uniform.

These extrusions are removed to form pellets by a pair of extrusion knives 93, each adjustably mounted in a bracket 95 against the discharge surface of the ring die and associated with the output of one of the extrusion rollers. The pellets thus formed will discharge through the opening in the bottom of the extrusion cham ber housing for packaging.

The pellet material feeding mechanism described above has resulted in a remarkably increased yield from pellet .mills of the type described, in one instance involving the pelleting of alfalfa, increasing the previous normal yield of 2100 pounds per hour in a machine using conventional feeding mechanism, to a' yield of approximately 7500 pounds per hour in a similar machine utilizing the improved feeding mechanism of the present invention.

It will be apparent from the foregoing, that the present invention fulfills all the objects attributable thereto, and while I have disclosed my invention in its preferred form, the same is subject to alteration and modification without departing from the underlying principles involved, and I,

compression surface.

3. In a pellet mill having an extrusion chamber including a rotatable ring die and stationary extrusion means movable relatively with respect to the compression surface of said die, means for supplying pellet material to said extrusion chamber, and means for spreading the material delivered from said supplying means on said compression surface, said means including a stationary deflectorspreader element comprising substantially an arcuateshaped blade extending into said extrusion chamber across the compression surface of said ring die on an angle to the U axis of the extrusion chamber in the general direction of rotation of said ring die, with the outer edge of such blade uniformly spaced from said compression surface.

4. In a pellet mill having an extrusion chamber including a ring die and extrusion means movable relatively with respect to the compression surface of said die, means for supplying pellet material to said extrusion chamber comprising a substantially cylindrical casing aflixed at one end to the front edge of said ring die and terminating at its other end in a front wall having a feed opening there-- in and an inwardly directed lip bounding said feed opening, a feed hopper having a cylindrical lower end in alignment with and extending into the feed opening of said casing, means within said cylindrical lower end for driving material from said feed hopper into said casing, said means including a plurality of spiral blades, and means supporting said spiral blades in spaced relationship to each other on a common axis within said cylindrical lower end of said feed hopper.

5. In a pellet mill having an extrusion chamber including a ring die and extrusion means including at least one roller movable relatively with respect to the compression surface of said die, means for supplying pellet material to said extrusion chamber comprising a substantially cylindrical thin wall casing aifixed at one end to the front edge of said ring die and terminating at its other end and in a front wall having a feed opening therein and an inwardly directed lip bounding said feed opening, a feed hopper having a cylindrical lower end in alignment with and extending into the feed opening of said casing, means within said cylindrical lower end for driving material from said feed hopper into said casing, said means including a plurality of spiral blades, means supporting said spiral blades in spaced relationship to each other on a common axis within said cylindrical lower end of said feed hopper, said supporting means comprising a plurality of brackets distributed about said feed opening and atfixed to the inner side of the front wall of said casing, with an end of each of said spiral blades afiixed to at least a pair of said brackets, and a spider interconnecting said spiral blades together at their free ends, and means for spreading the material from said supplying means on said compression surface.

6. In a pellet mill having an extrusion chamber including a ring die, and extrusion means including a pair of rollers movable relatively with respect to the compression surface of said die, means for supplying pellet material to said extrusion chamber comprising a substantially cylindrical thin wall casing afiixed at one end to the front edge of said ring die and terminating at its other end in a front wall having a feed opening therein and an inward directed lip bounding said feed opening, a feed hopper having a cylindrical lower end in alignment with and extending into the feed opening of said casing, means within said cylindrical lower end for driving material from said feed hopper into said casing, said means including a plurality of spiral blades, means supporting said spiral blades in spaced relationship to each other on a common axis within said cylindrical lower end of said feed hopper, said supporting means comprising a plurality of brackets uniformly distributed about said feed opening and affixed to the inner side of the front wall of said casing, with an end of each of said spiral blades aflixed to at least a pair of said brackets, and a spider interconnecting said spiral blades together at their free ends, and means for spreading the material delivered from said supplying means on said compression surface, said means including a pair of deflector-spreader elements, each comprising an arcuate-shaped blade extending on an angle to the axis of the extrusion chamber in the general direction of rotation of said ring die, from a point adjacent the front wall of said casing to a point in said extrusion chamber beyond the path of relative travel of said rollers, with the outer edge of such blade uniformly close to the cylindrical wall of said casing and uniformly spaced from said ring die.

7. In a pellet mill having an extrusion chamber including a ring die and extrusion means movable relatively with respect to the compression surface of said die, and means for supplying pellet material to such extrusion chamber comprising a feed hopper having a cylindrical lower end directed toward such extrusion chamber; a coreless screw type feed means for driving material from said feed hopper toward said extrusion chamber, said coreless screw type feed means including a plurality of independent spiral blades and means holding said spiral blades in spaced relationship to each other on a common axis within the cylindrical lower end of said feed hopper.

8. In a pellet mill having an extrusion chamber including a ring die and extrusion means movable relatively with respect to the compression surface of said die, and means for supplying pellet material to such extrusion chamber comprising a feed hopper having a cylindrical lower end directed toward such extrusion chamber; a coreless screw type feed means for driving material from said feed hopper toward said extrusion chamber, said coreless screw type feed means being located within the cylindrical lower end of the feed hopper in spaced relationship thereto and including a plurality of independent spiral blades and means holding said spiral blades in spaced relationship to each other on a common axis within the cylindrical lower end of said feed hopper, said holding means being located at one end only of said spiral blades.

9. In a pellet mill having an extrusion chamber including a ring die and extrusion means movable relatively with respect to the compression surface of said die, and means for supplying pellet material to such extrusion chamber comprising a feed hopper having a cylindrical lower end directed toward such extrusion chamber; a coreless screw type feed means for driving material from said feed hopper toward said extrusion chamber, said coreless screw type feed means being located within the cylindrical lower end of the feed hopper in spaced relationship thereto and including a plurality of independent spiral blades and means holding said spiral blades in spaced relationship to each other on a common axis within the cylindrical lower end of said feed hopper, said holding means being located at one end only of said spiral blades, and means interconnecting said spiral blades together at their free ends independently of the cylindrical lower end of said hopper.

References Cited in the file of this patent UNITED STATES PATENTS 2,063,404 Selman Dec. 8, 1936 2,240,660 Meakin May 6, 1941 2,295,743 Meakin Sept. 15, 1942 

